code: def test_categorical_reductions(op):
      gsr = cudf.Series([1, 2, 3, None], dtype="category")
      psr = gsr.to_pandas()
  
      utils.assert_exceptions_equal(getattr(psr, op), getattr(gsr, op))
  
imports: from decimal import Decimal
  from itertools import product
  import numpy
  import pandas
  import pytest
  import cudf
  from cudf import Series
  from cudf.core.dtypes import Decimal32Dtype, Decimal64Dtype, Decimal128Dtype
  from cudf.testing import _utils
  from cudf.testing._utils import NUMERIC_TYPES, assert_eq, expect_warning_if, gen_rand
label_desc: Use image node_id 17 for calling a global function with example usage: test_categorical_reductions(op) without return types